In a catalytic converter that is provided at an exhaust pipe in order to purify the exhaust generated at an internal combustion engine, it is desirable to supply electricity to a catalyst support, that is formed of metal and supports a catalyst, and raise the temperature of the catalyst support so as to obtain a sufficient catalytic effect. For example, when electricity is supplied to a catalyst support (base material), whose cross-section orthogonal to the direction in which the exhaust flows is circular, by a pair of electrodes that are affixed to opposing positions with this catalyst support therebetween, the cross-sectional surface area in the direction in which the current flows differs greatly in the vicinity of the electrodes and at the center of the catalyst support. Therefore, a large difference arises in the current density as well, and it is easy for non-uniformity of the amount of heat that is generated to arise.
In contrast, for example, Patent Document 1 discloses a catalyst support whose cross-section orthogonal to the direction in which the exhaust flows is quadrilateral. At this catalyst support, the sectional surface area of the flow of current is uniform, and therefore, it is difficult for the aforementioned non-uniformity of the generated amount of heat to arise. However, when the heat dissipation from the electrodes becomes large, the balance between heat generation and heat dissipation collapses, and the temperature difference within the catalyst support becomes large.    Patent Document 1: Japanese Patent Application Laid-Open No. 4-280086